Mercury vapor lamp



June 2, 1931. M. MORRISON MERCURY VAPOR LAMP Filed'Feb. s. 1929 Patented June 2, 1931 UNITED STATES PATENT OFFICE MON'I'FORD MORRISON, OF CHICAGO, ILLINOIS, ASSIG-NOR, BY MESNE ASSIGNMENTS, TO WESTINGHOUSE LAMP COMPANY, A CORPORATION OF PENNSYLVANIA MERCURY VAPOR LAMP Application filed. February 8, 1929. Serial No. 338,477.

ployed is of an order above that necessarily re uiring iron in the induction circuit.

mong the objects of my inventlon are; to produce an electric lamp which operates without the use of sealed-in electrodes, to-

produce a gaseous conduction or vapor lamp which has no critical starting voltage, to produce an'arc lamp in which the arc length may be varied at will andthereby vary the arc characteristics associated therewith, to produce an induction lamp in which the heated energy can be confined to definite circuits, and to produce an induction lamp in which the heating circuit can be resonated with the other associated circuits, thereby obtaining a maximum energy for that circuit under a given set of conditions.

Other and further objects will be obvious and pointed out in the specification, but the novel features of my invention are more particularly set forth in the claims.

In this specification, the term vapor and its derivatives are used to include also the conception of gas.

In the accompanying drawings, I have shown one embodiment of my invention with some variations therein, in which Fig. 1 is in part an elevation and in part a diagrammatic drawing of a simple embodiment of my invention.

Figs. 2, 3, 4 and 5 are some of the ex lanatory details in Fig. 1, Figs. 6 and are modifications of some of the elements of Fig. 1.

In Fig. 1, l is an alternating current generator which, through leads 2 and 8, supplies energy to primary 4 of the step-up transformer 5, the secondary 6 of which is shunted by a suitable spark gap 7 and also I connected to condensers 8 and 9, the opposite plates of which are connected to a helix having a fraction of one or more turns of conductor 10. This much of the figure illustrates a common high frequency circuit employing a Tesla transformer, of which is formed by the helix 10. A flexible connector 11 is provided for the purpose of adjusting the reactance of the circuit for tuning.

The lamp proper, in its simplest form, is illustrated by 12, which is a hollow toroid of non-conducting translucent material which, in the figure, is held by the clamp 13 and has upon its annular surface a coil or wire 14, which is connected in circuit the primary with a battery 15 and a means for adjusting the current in the circuit thereof 16.

The term translucent material is used to mean that some part, of the element of the device referred to, is constructed of translucent material but not necessarily entirely of translucent material.

In this specification the term lamp is used to mean substantially the entire apparatus shown in Fig. 1 or the lamp proper which is member 12 of that figure, dependmg upon which is applicable.

In Fig. 2 is shown a vertical cross section v of the hollowtoroid 12 which may contain within its hollow space 17, a vapor, a liquid a solid or any combination of these.

For purposes of illustrating one embodiment of my invention, I will describe a-lamp containing mercury. the hollow toroid 12 Fig. 2 a mercury level will be observed in 18.

If the geometrical figure of'the hollow toroid 12 as illustrated,-contains a sufficient amount of mercury, when this toroid is held in a horizontal position, the mercury will assume a continuous ring, forming a complete circuit of electrical'con'ductor as illustrated in Fig. 3, which is a horizontal cross section of Fig. 2, showing the mercury surface 18 from this point of view.

It will be appreciated by those familiar with the art to' which my tains that the exact geometrical form of my In the lower part of invention apperlamp is not an essential element of my invention. A circular lamp is described merely for clearness and simplicity any suitable geometric figure whatever may be used, provided it comes within the scope of myclaims.

the lamp or Referring to Fig. 4, which is a cross section similar to Fig. 2, it will be observed that when the toroid 12 is tilted slightly, the mercury will part at 19, as illustrated in Fig. 5, which is a cross section similar to Fig. 3, but held in the position shown in in hollow member 12, as to permit its complete vaporization during starting of the lamp allowing the lamp to start with a complete circuit of mercury and operate on pure mercury vapor or mercury vapor mingled with such inert gases as I may choose to introduce into the chamber 17 before sealing the envelope 12 hermetically. Among the suitable gases which may be used sometimes to advantage in member 12, may be mentioned; argon, krypton, neon and xenon.'

Such gases may be so proportioned asto ass1st in providing desirable electrical operatmg characteristics for the lamp or to influence the s ecilzlrum of the light emitted by The coupling between primary 10 and secondary 12 is adjusted by moving the secondary withreference to the primary or yisa versa and thereby adjusting the energy lnput into the secondary 12, thereby affecting the light output of the lamp.

The envelop member 12 may be made by any suitable method, depending upon what is desired with reference to spectrum and electrical operating characteristics.

The pressure in the chamber 17 may have any desired value and may be -'even superatmospheric,

The coil'l in Fig. 1 forms one means for adjusting the temperature of the lamp. That is, instead of providing an excess input energy into the lamp and then providing cooling means for radiating some of the excess heat, I may in some instances provide, by induction, heat energy for the lamp less than that required for proper operation, and adjust the temperature of the lamp by means of current ad ustor 16.

The intensity of the light emitted by the lamp is dependent, for one thing, upon the the whole oscillator an a secondary for the Tesla transforme'r l0.

An electric current is induced into closed lamp circuit within 12.

It may be pointed out that between .my present invention and induction lamps of the prior. art the essential difference hes in the fact that the induced E. M. F. must exceed a certain critical voltage known as the ionization potential before vapor becomes conducting in induction lamps of the prior art, whereas in my invention no such critical voltage is present.

In my invention, the-lamp, starting out with a continuous circuit conductor, has an arc instituted as soon as the conductor is broken by tilting the lamp, Whereas in lamps of the prior art it is necessary to operate the lamp itself within a very intense magnetic field, and this field intensity must reach a critical value before the lamp will operate at all.

In the present invention the lamp is further characterized and difi'erentiated from the prior art induction lamp by the fact that my lamp proper does not have to be located within an intense magnetic field and may be in cases, to a considerable advantage, located outside of the field.

The heating in the induction lamp of the prior artis analogous to the heating of the core by eddy currents in a transformer whereas in the present invention the heating is related to a short-circuited conductor around the core of a transformer.

The use of a definite circuit for the lamp conductor ath, as embodied in my invention, whetl ier the conducting medium be vapor-plus, liquid or solid, has the effect of producing electrically a clean-cut reactance not present :in induction lamps of the prior art. This reactance element of my invention permits the lamp circuit to be tuned by means of adjusting the other reactance associated with the lamp, for instance by moving conductor 11 in Fi 1. 'By so doing the lamp circuit, can be brought into resonance providing a' maximum energy input into the lamp for a given set of conditions, as. well as a higher overall efiiciency for the system.

Fig. 6 shows a modification of the lamp above described "in which the helix 20 is internal of the lamp proper 21, which permits certain advantages in some cases.

" While I have described in the foregoing embodiment a single turn of electrical conductor, this is quite obviously not a limitation of the invention, and in Fig. 7, I have circuit, including illustrated a lamp containing a primary 22 composed of several convolutions' and a lamp secondary 23 composed of several similar convolutions and placed closely adja-' cent thereto.

In this case the convolutions 23 can be made of very small tubing, and inexpen-' sively. The tubing 23 is brought out to wells 24 and 25. When the lamp illustrated in Fig. 7 is tilted to a certain position, the conductor in tubing 23 becomes continuous, and when tilted to a second position the conductor is broken at the space 26 providing the are for the lamp. A contact between electrodes 24 and 25 is accomplished by tilting the lamp away from the reader, as will be understood from inspection of the drawings. The are len th is determined by the operating position of the lamp, which determines the level of the mercury in the chamber 26, the chamber being so formed that the level of the mercury is affected by the angle ofthe lamp.

I have described one embodiment of invention, and, therefore, I claim:

1. In a luminous discharge device, a hollow translucent hermetically sealed envelope containing a medium subject to conduction.

of electric current, a source of magnetic field energy inductively associated with said medium, and a source of heat adjacent said envelope whereby the mean operating temperature of the said device is partly determined by the said field energy and partly determined by the said source of heat.

2. In an induction lamp, a source of alternating current of a frequency in excess of .5000 cycles per second, a primary inductance coil electrically associated with said source, a hollow translucent tube-formed into an endless hermetically sealed envelope located adjacent said coil, said envelope containing an electrically conductive medium cooperating inductively with said coil, the path of the current in the said medium due to said inductive cooperation having a predeter- 'mined electrical self-inductance under operation, whereby the energy in the said medium under operation is partly determined by the electrical reactance of the current in the circuit of the said medium upon the current in the circuit of the aforesaid primary coil and partly primary circuit.

3. In an induction lamp, a source of oscillating current of a frequency in excess of 5000 cycles per second, a primary inductance coil electricallyassociated with said source, a hollow translucent tube formed into an endless hermetically sealed envelope located adjacent said coil and having a geometrical form possessing an inductance value of at least several per cent of 'that'of the afore-. said primary coil, said envelope containing an electrically conductive medium cooperatby 'the characteristics of the ing inductively with said coil and luminescent under electrical excitation, whereby the natural period of the current of the aforesaid source is determined over a range of several per cent by the reactance of the current fiow in the said tube under operation.

4. In an induction lamp, a source of oscillating current of a frequency in excess of 5000 cycles per second, a primary inductance coil electrically associated with said source, a hollow translucent tube formed into an endless hermetically sealed envelope located adjacent said coil and having a geo- I metrical form possessing an inductance value of at least several per cent of that of the aforesaid primary coil, said envelope containing an electrically conductive medium cooperating inductively with said coil and luminescent under electrical excitation, whereby the frequency of the alternations of the current of the aforesaid source is dependent upon the relation of the reactance proper of the current in the luminescent medium to the total reactance of the combined circuits over a range of several per cent thereof, under operation.

5. In an induction lamp, a source. of oscillating current of a frequency in excess of 5000 cycles per second, a primary inductance coil electrically associated with said source, a hollow translucent tube constituting an endless hermetically sealed envelope,

said tube containing a medium conductive to electric current, luminescent under electrical excitation, and inductively associated with aforesaid coil, said tube being formed to include within said medium a minimum of the alternating magnetic field flux of said coil and to embrace a maximum thereof, under operation.

6. In an induction lamp, a source of oscillating current of a frequency in excess of 5000 cycles per second, a primary inductance coil electrically associated with said source a hollow translucent tube constituting an endless hermetically sealed envelope, said tube containing a medium conductive to electric current, luminescent under electrical excitation, and inductively associated with aforesaid. coil, said tube being formed taining' an electrically conducting liquid partly completing the circuit of the said tube and further containing an electrically conducting vapor, said conducting liquid and said va or cooperating inductively with said coil, w ereby the conduction of electric current in the circuit of the said tube under operation is partly through said liquid and V partly through said vapor.

8. In an induction lamp, a source of alternating current of a frequency in excess of 5000 cycles per second, a primary inductance coil electrically associated with said source, a hollow translucent tube formed into an endless hermetically sealed envelope located adjacent said coil, said tube containing a complete circuit of liquid in an unexcitedstate which said liquid is conductive to electric current by induction from said primary coil, whereby the said liquid becomes completely vaporized under operation and the electrical conduction in changes from liquid conduction to vaporous conduction under operation.

9. In an induction lamp, a source of alternating current of a frequency in excess of 5000 cycles per second, a primary inductance coil electrically associated with said source, a hollow translucent tube formed into an endless hermetically sealed envelope located adjacent said coil, said tube containing an electrically conducting solid partly completing the circuit of the said tube,

and further containing an electrically conducting vapor, said conducting solid and said vapor cooperating inductively with said coil, whereby the conduction of electric 4 current in the circuit of the said tube under operation is partly through said solid and partly through sald vapor.

MONTFORD MORRISON. 

